Conventionally, as disclosed in Patent Literature 1, the present applicant considers a water quality measuring device in which a plurality of solutions are displayed in order to easily retrieve the solutions when an error occurs.
Specifically, in this water quality measuring device, if an error occurs, the occurrence of the error is displayed on a screen where a measurement value is indicated. Then, upon depression of a help key provided on an upper surface of the device body in this state, an outline of a plurality of solutions is displayed together with displaying, e.g., an error content of “calibration/incorrect potential error”. Then, by selecting a solution which is likely to be appropriate as a solution for the error content among the plurality of solutions, a concrete solution is displayed.